Cosmos Computed

About a week ago, I was finally able to observe the second solar eclipse of my life – a partial eclipse with a maximum coverage of about 50%. The only other eclipse I have observed was another  partial solar eclipse in May 2012 . A solar eclipse occurs when the moon casts its shadow on Earth's surface. From the point of view of an observer in the shadow, the moon covers the sun. It's not always obvious when a solar eclipse is happening; if the observer is in near the edge of the shadow, so the sun is only partly covered, it might not seem like anything unusual is happening. This was my situation during the eclipse last week. The moon only covered part of the sun, so when I told one of my friends that an eclipse was occurring, he hadn't even realized it. And I don't blame him. Actually, a few minutes earlier, I hadn't realized it either. I got the time mixed up, and didn't think the eclipse had begun yet. The sunlight was weaker than usual, but I assumed that was...

If time were stopped, would this falling pen look blurry to us? Time can be a very confusing subject. It has a past, a present, and a future, but the future keeps changing and the present is always moving, while the past grows larger. Although most people think they understand time, they often get confused when they try to describe it. To help visualize and understand time, many people compare it to a very familiar concept: a line. This line, called a timeline, represents time as a whole. The current moment, or the present, is a single point which moves smoothly along the timeline. The part of the timeline behind the point is the past, and the part ahead of the point represents the future. The whole timeline, including the moving point that represents the present, is considered exactly the same for everyone. Although this whole approach may be a useful way to represent time, it is actually inaccurate in describing time. First of all, the present does not have to be experienced in the s...